Barracks
A Barracks is drill yards, armouries and lodgings, raised on Wilderness. It organises recruitment: it is where ordinary folk become soldiers.
Every recruit is one of the kingdom's own people, and recruiting one costs geld and a person. Drilled soldiers are Plain: whatever affinity their lord's core holds, they carry none. Recruits can normally be sent home when they are no longer needed. A few folk live in the lodgings as well.
Pay keeps them. Unpaid soldiers desert, and the Barracks itself costs geld to keep; when geld runs short, buildings are abandoned. In a coreless lineage, soldiers such as Man-at-Arms and Sapper serve the lord's given word as well as their pay, but even they must be paid.